The present invention relates to an electric power conversion apparatus which allows short-time recovery from a partial failure.
Some electric power conversion apparatuses are used to convert a three-phase alternating current power source into a direct current power source to drive electric motors etc. On the other hand, there are other electric power conversion apparatuses which convert a direct current power source into a three-phase alternating current power source and supply the alternating current power source to an electric power system etc. Among known examples of such electric power conversion apparatuses is one disclosed in Japanese Patent Application Laid-Open Publications No. 2002-354840, the entire content of which is incorporated herein by reference.
An electric power conversion apparatus typically includes a U-phase conversion unit, a V-phase conversion unit, and a W-phase conversion unit which correspond to a three-phase alternating current. The U-phase conversion unit has the function of converting a direct current into a current component corresponding to a current component of a three-phase alternating current corresponding to a U phase, and the function of converting a U-phase current into a direct current. The V-phase conversion unit and the W-phase conversion unit each have similar functions to those of the U-phase conversion unit.
These conversion units are arranged inside a control panel or the like. The conversion units each may have leading parts or the like that are intended for easy insertion and extraction into/from the control panel. Such a configuration facilitates a recovery operation since a conversion unit corresponding to one phase, if failed, can be easily replaced with a replacement conversion unit. Wiring in the vicinity of the leading parts and the like is often complicated and high in cost. Complicated wiring can sometimes lower energization efficiency.
A U-phase conversion unit, a V-phase conversion unit, and a W-phase conversion unit are sometimes directly attached to a substrate that is arranged in a casing, for example. Such a configuration allows more compact arrangement of the conversion units. The absence of leading parts and the like can accordingly simplify the wiring for lower manufacturing costs.
If the conversion units are configured to be directly attached to a substrate or the like, it may take a long time to replace a failed conversion unit. Electric power conversion apparatuses are often used to drive plant and other equipment such as electric motors, and can rarely be stopped for a long time. A failure recovery operation therefore needs to be performed in a short time.